Microbiology Principles And Explorations 8th Edition – by Jacquelyn G. Black – Test Bank A+

$35.00
Microbiology Principles And Explorations 8th Edition – by Jacquelyn G. Black  –  Test Bank A+

Microbiology Principles And Explorations 8th Edition – by Jacquelyn G. Black – Test Bank A+

$35.00
Microbiology Principles And Explorations 8th Edition – by Jacquelyn G. Black – Test Bank A+

Chapter 5: Essential Concepts of Metabolism

Question Type: Multiple Choice

1) The synthesis of DNA, in which small nucleotides are joined together to make a single large molecule would be most correctly described as being a/n ________ reaction.

  1. a) metabolic
  2. b) anabolic
  3. c) catabolic
  4. d) cytobolic

Answer: b

Difficulty: Easy

Learning Objective 1: LO 5.1 Explain how anabolism and catabolism are interrelated and metabolic processes that occur in cells.

Section Reference 1: Section 5.1 Metabolism: An Overview

2) Oxidation is defined as the ________ while reduction is the ________ .

  1. a) gain of electrons, loss of protons
  2. b) loss of electrons, gain of protons
  3. c) loss of electrons, gain of electrons
  4. d) loss of protons, gain of protons

Answer: c

Difficulty: Medium

Learning Objective 1: LO 5.1 Explain how anabolism and catabolism are interrelated and metabolic processes that occur in cells.

Section Reference 1: Section 5.1 Metabolism: An Overview

3) Photoautotrophs obtain energy from:

  1. a) light and use carbon dioxide as a carbon source
  2. b) organic molecules and use carbon dioxide as a carbon source
  3. c) inorganic substances and use carbon dioxide as a carbon source
  4. d) light and use organic substances as a carbon source

Answer: a

Difficulty: Medium

Learning Objective 1: LO 5.1 Explain how anabolism and catabolism are interrelated and metabolic processes that occur in cells.

Section Reference 1: Section 5.1 Metabolism: An Overview

4) Organisms which get their carbon from other organisms are:

  1. a) autotrophs
  2. b) chemotrophs
  3. c) phototrophs
  4. d) heterotrophs

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.1 Explain how anabolism and catabolism are interrelated and metabolic processes that occur in cells.

Section Reference 1: Section 5.1 Metabolism: An Overview

5) Animals (humans for example) are:

  1. a) photoautotrophs
  2. b) photheterotrophs
  3. c) chemoautotrophs
  4. d) chemoheterotrophs

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.1 Explain how anabolism and catabolism are interrelated and metabolic processes that occur in cells.

Section Reference 1: Section 5.1 Metabolism: An Overview

6) Degradation reactions where large molecules are broken down into smaller molecule is referred to as:

  1. a) metabolism
  2. b) catabolism
  3. c) biosynthesis
  4. d) anabolism

Answer: b

Difficulty: Easy

Learning Objective 1: LO 5.1 Explain how anabolism and catabolism are interrelated and metabolic processes that occur in cells.

Section Reference 1: Section 5.1 Metabolism: An Overview

7) Chemoautotrophic bacteria obtain the energy they need from:

  1. a) the reactions of photosynthesis
  2. b) sunlight
  3. c) carbon dioxide in the atmosphere
  4. d) chemical reactions in their cytoplasm centered around the use of inorganic substances

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.1 Explain how anabolism and catabolism are interrelated and metabolic processes that occur in cells.

Section Reference 1: Section 5.1 Metabolism: An Overview

8) Enzymes work by:

  1. a) lowering the energy of the reactants.
  2. b) raising the energy of the products.
  3. c) decreasing the activation energy of the reaction.
  4. d) increasing the activation energy of the reaction.

Answer: c

Difficulty: Easy

Learning Objective 1: LO 5.2 Describe the structure and properties of enzymes.

Section Reference 1: Section 5.2 Enzymes

9) An enzyme-substrate complex forms when substrate binds to an enzyme at the enzyme’s ______ site.

  1. a) catalytic
  2. b) allosteric
  3. c) operative
  4. d) active

Answer: d

Difficulty: Easy

Learning Objective 1: LO 5.2 Describe the structure and properties of enzymes.

Section Reference 1: Section 5.2 Enzymes

10) A holoenzyme consists of:

  1. a) an apoenzyme plus a cofactor
  2. b) an apoenzyme plus a coenzyme
  3. c) an protein and non-protein component
  4. d) all of the above

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.2 Describe the structure and properties of enzymes.

Section Reference 1: Section 5.2 Enzymes

11) Which statement is true about enzymes?

  1. a) Enzyme catalyzed reactions would not go forward without their specific enzymes.
  2. b) Most enzymes catalyze several different reactions.
  3. c) Coenzymes are organic molecules while cofactors are inorganic molecules.
  4. d) An apoenzyme is a holoenzyme that is missing its cofactor.

Answer: c

Difficulty: Medium

Learning Objective 1: LO 5.2 Describe the structure and properties of enzymes.

Section Reference 1: Section 5.2 Enzymes

12) Competitive inhibition of enzymes occurs when the inhibitor:

  1. a) binds to the active site of the enzyme.
  2. b) binds to the allosteric site of the enzyme.
  3. c) inhibitor changes the shape of the enzyme.
  4. d) inhibitor is acted upon by the enzyme.

Answer: a

Difficulty: Easy

Learning Objective 1: LO 5.3 Describe competitive and noncompetitive enzyme inhibition and as well as other physical factors that can influence reaction rates.

Section Reference 1: Section 5.3 Enzyme Inhibition

13) Sulfa drugs bind to the active site of the enzyme which normally converts para-amino benzoic acid (PABA) to folic acid, preventing the production of folic acid and, eventually purine synthesis. In this case, the sulfa drug is acting as a/an:

  1. a) allosteric inhibitor
  2. b) competitive inhibitor
  3. c) noncompetitive inhibitor
  4. d) uncompetitive inhibitor

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.3 Describe competitive and noncompetitive enzyme inhibition and as well as other physical factors that can influence reaction rates.

Section Reference 1: Section 5.3 Enzyme Inhibition

14) Factors that affect the rate of enzyme catalyzed reactions include:

  1. a) temperature
  2. b) pH
  3. c) concentration of enzyme
  4. d) all of the above

Answer: d

Difficulty: Easy

Learning Objective 1: LO 5.3 Describe competitive and noncompetitive enzyme inhibition and as well as other physical factors that can influence reaction rates.

Section Reference 1: Section 5.3 Enzyme Inhibition

15) Which of the following statements about enzyme inhibition is true?

  1. a) Most noncompetitive inhibitors bind to several different sites on an enzyme.
  2. b) Enzymes become less efficient as temperatures drop because they begin to denature.
  3. c) Noncompetitive inhibitors bind to a site other than the active site.
  4. d) Most human enzymes have an optimum temperature below normal body temperature.

Answer: c

Difficulty: Hard

Learning Objective 1: LO 5.3 Describe competitive and noncompetitive enzyme inhibition and as well as other physical factors that can influence reaction rates.

Section Reference 1: Section 5.3 Enzyme Inhibition

16) How does concentration affect enzyme-catalyzed reactions?

  1. a) As the concentration of the product goes up the enzyme increases the rate it produces the product.
  2. b) Concentration does not affect enzyme-catalyzed reactions because they are irreversible.
  3. c) At chemical equilibrium, no net change in the concentration of the product or substrate occurs.
  4. d) The quantity of enzyme available usually controls the rate of a metabolic reaction.

Answer: c

Difficulty: Hard

Learning Objective 1: LO 5.3 Describe competitive and noncompetitive enzyme inhibition and as well as other physical factors that can influence reaction rates.

Section Reference 1: Section 5.3 Enzyme Inhibition

17) Which one of the following pairs is mismatched?

  1. a) Alcohol – Fermentation
  2. b) Pyruvate – Glycolysis
  3. c) Carbon dioxide – Glycolysis
  4. d) Oxaloacetic acid – Krebs cycle

Answer: c

Difficulty: Hard

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

18) Which of the following is not a carrier molecule that carries hydrogen atoms or electrons in oxidative reactions?

  1. a) Cytochrome
  2. b) FAD
  3. c) Niacin
  4. d) NAD+

Answer: c

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

19) In glycolysis, each molecule of glucose eventually produces ________ molecules of pyruvic acid.

  1. a) one
  2. b) two
  3. c) three
  4. d) four

Answer: b

Difficulty: Easy

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

20) Substrate level phosphorylation during glycolysis refers to the transfer of phosphate groups from:

  1. a) ATP to glucose
  2. b) 1,3 diphosphoglyceric acid to ADP
  3. c) phosphoenolpyruvic acid to ADP
  4. d) ATP to ADP

Answer: a

Difficulty: Medium

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

21) Which of the following is true about glycolysis?

  1. a) The net yield of ATP is two ATPs for each molecule of glucose.
  2. b) It provides cells with a relatively large amount of energy.
  3. c) Four molecules of ATP are used in the initial phosphorylation steps.
  4. d) The ATP that is used up during glycolysis is not considered in calculating the net yield of ATP.

Answer: a

Difficulty: Medium

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

22) During glycolysis, electrons are initially transferred to:

  1. a) NAD+
  2. b) FAD
  3. c) NADP
  4. d) H2O

Answer: a

Difficulty: Medium

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

23) The end product of glycolysis is:

  1. a) fructose-1,6-diphosphate
  2. b) 1,3 diphosphoglyceric acid
  3. c) phosphoenolpyruvic acid
  4. d) pyruvic acid

Answer: d

Difficulty: Easy

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

24) Pyruvic acid is metabolized in the absence of oxygen during the process of:

  1. a) glycolysis
  2. b) fermentation
  3. c) oxidation
  4. d) dark reactions

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

25) Organisms that can use oxygen for metabolic reactions but can also function in an environment devoid of oxygen are termed _____.

  1. a) aerobes
  2. b) anaerobes
  3. c) aerophiles
  4. d) facultative anaerobes

Answer: d

Difficulty: Medium (this is from Ch. 6, I suggest omitting it))

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

26) In fermentation reactions occurring in yeast to produce wine, two products of the reaction are __________ and _________.

  1. a) acid; hydrogen gas
  2. b) hydrogen gas; propionic acid
  3. c) ethyl alcohol; methane
  4. d) carbon dioxide; ethyl alcohol

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

27) All of the following are electron acceptors for anaerobic respiration, except:

  1. a) carbon dioxide
  2. b) oxygen
  3. c) nitrate ions
  4. d) sulfate ions

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

28) Which statement about fermentation is true?

  1. a) All fermentation of pyruvic acid always results in the same end product.
  2. b) All fermentation of glucose begins with pyruvic acid as a substrate.
  3. c) The same fermentation reaction produces both wine and cheese.
  4. d) None of the above

Answer: d

Difficulty: Hard

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation

29) The initial substrate molecule for the Krebs cycle is:

  1. a) pyruvic acid
  2. b) acetyl-CoA
  3. c) acetic acid
  4. d) butanediol

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

30) The electrons transferred from acetyl groups in the Krebs cycle are transferred to:

  1. a) NAD+ only
  2. b) FAD only
  3. c) neither NAD+ and FAD
  4. d) both NAD+ and FAD

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

31) Each acetyl-CoA molecule will eventually produce ________ in the Krebs cycle.

  1. a) four pairs of electrons
  2. b) three molecules of NADH
  3. c) one molecule of GTP
  4. d) all of these choices

Answer: d

Difficulty: Hard

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

32) In the electron transport chain, the energy to make ATP comes directly from _____.

  1. a) FAD
  2. b) NADH
  3. c) both FAD and NADH
  4. d) neither FAD nor NADH

Answer: c

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

33) In aerobic respiration, the final electron acceptor is:

  1. a) water
  2. b) oxygen
  3. c) sulfur
  4. d) coenzyme Q

Answer: b

Difficulty: Easy

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

34) The prokaryotic aerobic metabolism of glucose produces a total (net) of ________ molecules of ATP.

  1. a) 24
  2. b) 30
  3. c) 34
  4. d) 38

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

35) Which reaction takes place in the mitochondrial membrane?

  1. a) Glycolysis
  2. b) Fermentation
  3. c) Krebs cycle
  4. d) Electron transport chain

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

36) Electron transport chain:

  1. a) involves transfer of O2 to electrons in the substrate
  2. b) results in a net consumption of ATP
  3. c) can be thought of as electrons acting as fish increasing in energy as they jump up a waterfall
  4. d) none of the above

Answer: d

Difficulty: Hard

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

37) Chemiosmosis:

  1. a) forms ATP
  2. b) occurs in the cell membrane of prokaryotes
  3. c) uses a proton gradient to activate ATP synthase
  4. d) all the above

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

38) How is ATP formed by chemiosmosis?

  1. a) Charge difference of outer and inner membrane gives motive force to generate ATP
  2. b) Nitrates are used as their final electron acceptor
  3. c) The last step involves H2O to be split into O2
  4. d) All of the metabolites enter the Krebs cycle

Answer: a

Difficulty: Hard

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

39) During the metabolism of fats, the product of beta-oxidation enters:

  1. a) glycolysis
  2. b) Krebs cycle
  3. c) oxidative phosphorylation
  4. d) electron transport chain

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.6 Describe how the energy of lipid and protein molecules can be extracted using the carbohydrate catabolism pathways described in this chapter.

Section Reference 1: Section 5.6 The Metabolism of Fats and Proteins

40) The first step in protein metabolism is the breakdown of proteins into:

  1. a) nucleotides
  2. b) fatty acids
  3. c) amino acids
  4. d) coenzymes

Answer: c

Difficulty: Easy

Learning Objective 1: LO 5.6 Describe how the energy of lipid and protein molecules can be extracted using the carbohydrate catabolism pathways described in this chapter.

Section Reference 1: Section 5.6 The Metabolism of Fats and Proteins

41) Glucose is to photosynthesis as pyruvate is to:

  1. a) oxidative phosphorylation
  2. b) glycolysis
  3. c) fermentation
  4. d) Krebs cycle

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.6 Describe how the energy of lipid and protein molecules can be extracted using the carbohydrate catabolism pathways described in this chapter.

Section Reference 1: Section 5.6 The Metabolism of Fats and Proteins

42) The green sulfur and purple sulfur bacteria are capable of:

  1. a) carrying out photosynthesis
  2. b) only obtaining energy from organic molecules
  3. c) bypassing glycolysis for the Krebs cycle
  4. d) metabolizing without enzymes

Answer: a

Difficulty: Medium

Learning Objective 1: LO 5.7 Discuss the energy capture pathways used by photoautotrophs, chemoautotrophs, and photoheterotrophs.

Section Reference 1: Section 5.7 Other Metabolic Processes

43) In photosynthesis, light energy is used to:

  1. a) break down proteins
  2. b) phosphorylate ADP to form ATP
  3. c) synthesize carbohydrates
  4. d) two of these choices

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.7 Discuss the energy capture pathways used by photoautotrophs, chemoautotrophs, and photoheterotrophs.

Section Reference 1: Section 5.7 Other Metabolic Processes

44) In photosynthesis, chemical energy is used to make organic molecules in the:

  1. a) light reaction
  2. b) dark reaction
  3. c) hydrolytic reaction
  4. d) photophosphorylation reaction

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.7 Discuss the energy capture pathways used by photoautotrophs, chemoautotrophs, and photoheterotrophs.

Section Reference 1: Section 5.7 Other Metabolic Processes

45) In algae, the dark reactions of photosynthesis occur in the:

  1. a) cell membrane
  2. b) matrix of the mitochondria
  3. c) stroma of the chloroplast
  4. d) nucleus

Answer: c

Difficulty: Medium

Learning Objective 1: LO 5.7 Discuss the energy capture pathways used by photoautotrophs, chemoautotrophs, and photoheterotrophs.

Section Reference 1: Section 5.7 Other Metabolic Processes

46) What is returned to chlorophyll in cyclic photophosphorylation that is not returned in non-cyclic photoreduction?

  1. a) ATP
  2. b) Light
  3. c) Energy
  4. d) Electrons

Answer: d

Difficulty: Hard

Learning Objective 1: LO 5.7 Discuss the energy capture pathways used by photoautotrophs, chemoautotrophs, and photoheterotrophs.

Section Reference 1: Section 5.7 Other Metabolic Processes

47) A metabolic pathway that is involved in both breakdown and synthetic reactions is properly termed _____.

  1. a) catabolic
  2. b) amphibolic
  3. c) metabolic
  4. d) anabolic

Answer: b

Difficulty: Easy

Learning Objective 1: LO 5.8 Identify some of the important cellular processes that require energy.

Section Reference 1: Section 5.8 The Uses of Energy

48) The initial breakdown of glucose in a eukaryotic cell takes place in the _____.

  1. a) cytoplasm
  2. b) golgi
  3. c) nucleus
  4. d) cell membranes

Answer: a

Difficulty: Easy

Learning Objective 1: LO 5.8 Identify some of the important cellular processes that require energy.

Section Reference 1: Section 5.8 The Uses of Energy

49) A surfactant:

  1. a) lowers the surface tension at the bacterium’s posterior end allowing Myxococcus to glide
  2. b) is metabolized to produce phosphoenolpyruvate
  3. c) forms channels thorugh the outer membrane
  4. d) emits light as it returns to its unexcited state

Answer: a

Difficulty: Easy

Learning Objective 1: LO 5.8 Identify some of the important cellular processes that require energy.

Section Reference 1: Section 5.8 The Uses of Energy

50) Bioluminescent microbes:

  1. a) may have evolved to remove oxygen from the atmosphere
  2. b) are often beneficiaries of symbiotic relationships with a larger host, producing light in exchange for nutrients
  3. c) often have the enzyme luciferase which catalyzes the oxidation reaction that emits light
  4. d) all of the above

Answer: d

Difficulty: Medium

Learning Objective 1: LO 5.8 Identify some of the important cellular processes that require energy.

Section Reference 1: Section 5.8 The Uses of Energy

51) At which temperature do enzymes begin to denature?

  1. a) 20 degrees Celsius
  2. b) 30 degrees Celsius
  3. c) 40 degrees Celsius
  4. d) 50 degrees Celsius

Answer: c

Difficulty: Easy

Learning Objective 1: LO 5.3 Describe competitive and noncompetitive enzyme inhibition and as well as other physical factors that can influence reaction rates.

Section Reference 1: Section 5.3 Enzyme Inhibition

52) As electrons are passed from carrier to carrier, their energy changes. At which point in the chain, would you expect the energy of the electrons to be the lowest?

  1. a) A
  2. b) G
  3. c) C
  4. d) F
  5. e) E

Answer: b

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

53) As electrons are passed from carrier to carrier, their energy changes. At which point in the chain, would you expect the energy of the electrons to be the highest?

  1. a) A
  2. b) B
  3. c) C
  4. d) D
  5. e) E

Answer: a

Difficulty: Medium

Learning Objective 1: LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.5 Aerobic Metabolism: Respiration

Question Type: Essay

54) Describe the chemical characteristics of enzymes and indicate why they are important in the metabolism of large molecules and how they determine which metabolic pathways occur in a cell.

Answer: Enzymes are proteins that catalyze chemical reactions by lowering the activation energy needed for a reaction to occur. They have an active site, where the binding of the substrate attaches and which shows a high degree of specificity. In addition, enzymes are not consumed in the reactions that they catalyze, allowing enzymes to continually catalyze reactions as long as the substrate is present and the conditions remain favorable. Almost all processes in a cell need enzymes in order to accelerate the rate of the reactions. This is particularly true of the metabolism of large molecules.

Other molecules (such as inhibitors, coenzymes, cofactors) along with the temperature and the amount of substrate available, can affect enzyme activity. Because enzymes are extremely selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes present in a cell helps determine which metabolic pathways are active at any time within a cell.

Difficulty: Medium

Learning Objective 1: LO 5.2 Describe the structure and properties of enzymes.

Section Reference 1: Section 5.2 Enzymes

55) Compare anaerobic and anaerobic respiration in terms of energy yields and reactants within the pathways. Anaerobic respiration and fermentation are both pathways that may occur in the absence of oxygen. Which confers a greater advantage to the cell? Why is the less advantageous pathway in existence within cells at all?”

Answer:. Aerobic and anaerobic respiration differ in their final electron acceptors. Aerobic respiration uses oxygen while other forms of anaerobic respiration uses inorganic molecules (such as nitrate, nitrite and sulfate). The energy yield of aerobic respiration is somewhat higher than that of aerobic respiration due to differing electron carriers within the electron transport chain. Both these pathways yield large quantities of ATP while fermentation yields none.

Fermentation is not a form of respiration since respiration is a pathway characterized by the activities of the Krebs cycle to oxidize carbon skeletons and an electron transport chain to extract the energy from high energy electron carriers such as NADH and FADH2Fermentation is a contingency pathway, allowing cells that lack the genes encoding for respiration enzymes and carriers to reoxidize NADH and make NAD+ available to drive glycolysis.. They will at least allow glycolysis to continue to supply the cell with small amounts of energy.. In addition, a wide range of carbohydrates and proteins can serve as substrates for microbial fermentation, which allows for microorganisms that ferment access to a wide variety of catabolic options.

Difficulty: Hard

Learning Objective 1: LO 5.4 Examine anaerobic biochemical pathways within the cell in terms of their substrates, products, and energy yields. LO 5.5 Compare the energy yield from aerobic respiration with that of fermentation through a description of the Krebs cycle, the electron transport chain, and chemiosmosis.

Section Reference 1: Section 5.4 Anaerobic Metabolism: Glycolysis and Fermentation; Section 5.5 Aerobic Metabolism: Respiration

56) What are chemoheterotrophs and how do they obtain energy? Name and describe two other ways microorganisms obtain energy. Why do you think so many different ways of obtaining energy evolved?

Answer: Chemoheterotrophs derive energy from organic molecules that they ingest, as they are dependent on others to make the molecules. Other ways to obtain energy include photoautotrophy, photoheterotrophy, and chemoautotrophy. Photoautotrophs obtain energy by using light energy to synthesize carbohydrates from inorganic carbon sources. Photoheterotrophy also uses sunlight as a source of energy but in this case the microbes require organic compounds as sources of carbon. Chemoautotrophic bacteria are unable to carry out photosynthesis but instead oxidize inorganic substances (such as nitrogen compounds, sulfur, iron and hydrogen) for energy and also utilize inorganic carbon sources for anabolism.

Many different metabolic lifestyles evolved because competition is fiercest between organisms that are dependent on the same nutrients. This can be explained through either competitive exclusion or niche expansion. In competitive exclusion, when any two organisms are dependent on the same nutrient and live in the same environment, eventually the more efficient consumer of that nutrient will drive the other to extinction. Another way to explain why there are so many lifestyles is to consider the lack of competition that an organism encounters when they alone are able to metabolize a particular nutrient. For example if many organisms encounter a location with some glucose and lots of nitrogen, then while all the other organisms are competing to secure the available glucose the organism that can use the nitrogen will be the most fit.

Difficulty: Medium

Learning Objective 1: LO 5.7 Discuss the energy capture pathways used by photoautotrophs, chemoautotrophs, and photoheterotrophs.

Section Reference 1: Section 5.7 Other Metabolic Processes

Chapter 6: Growth and Culturing of Bacteria

Question Type: Multiple Choice

1) Most bacteria reproduce by:

  1. a) sexual reproduction
  2. b) binary fission
  3. c) budding
  4. d) homologous recombination

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

2) The type of cell reproduction in which a small, new cell develops from the surface of an existing cell and then separates from the parent cell is known as ________ and is the normal mode of replication in _____ .

  1. a) binary fission, bacteria
  2. b) binary fission, yeast
  3. c) budding, bacteria
  4. d) budding, yeast

Answer: d

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

3) When a bacterial cell divides into two new cells, the new cells are called:

  1. a) daughter cells
  2. b) sister cells
  3. c) son cells
  4. d) father cells

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

4) Microbial growth:

  1. a) refers to the increase in the size of a microbial cell
  2. b) refers to the increase in the frequency of cell division
  3. c) in a single generation time leads to double the cell size
  4. d) in a single generation time leads to double the number of microbes.

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

5) Which of the following is not one of the phases of bacterial growth?

  1. a) Lag phase
  2. b) Stationary phase
  3. c) Doubling phase
  4. d) Log phase

Answer: c

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

6) A bacterial population grows most rapidly during ________ phase.

  1. a) lag
  2. b) log
  3. c) stationary
  4. d) death

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

7) In the stationary phase of bacterial growth:

  1. a) the number of newly generated cells is greater than the number of dying cells
  2. b) the number of newly generated cells is less than the number of dying cells
  3. c) the number of newly generated cells is the same as the number of dying cells
  4. d) none of the above

Answer: c

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

8) A bacterial culture can be kept in the log phase of growth indefinitely with the help of a/an:

  1. a) incubator
  2. b) chemostat
  3. c) spectrophotometer
  4. d) colony counter

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

9) Serial dilutions are used to:

  1. a) slow down the growth of microbes
  2. b) speed up the growth of microbes
  3. c) obtain bacterial cultures at several different concentrations
  4. d) form bacterial colonies

Answer: c

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

10) Which of the following counting techniques does not differentiate between live and dead bacterial cells in a culture?

  1. a) Serial dilution
  2. b) Spread plate
  3. c) Pour plate
  4. d) Direct microscopic count

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

11) Which of the following bacterial counting techniques relies on a statistical estimate to determine the number of bacteria in a culture?

  1. a) Serial dilution
  2. b) Standard plate count
  3. c) Spread plate
  4. d) Most probable number

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

12) Most bacteria:

  1. a) exhibit synchronous growth under natural conditions
  2. b) divide when a small new cell develops from the surface of an existing cell
  3. c) do not immediately increase in number when placed in a culture
  4. d) immediately begin to divide when placed in a culture

Answer: c

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

13) Bacterial growth in colonies on agar plates _____.

  1. a) have all phases of growth occurring simultaneously somewhere in the colony
  2. b) most growth occurs at the center of the colony
  3. c) involves budding of small new colonies from the surface of an existing colony
  4. d) have lag phase cells in the center of the colony, surrounded by a ring of cells in exponential phase

Answer: a

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

14) Turbidity in a bacterial culture can be measured using a/an:

  1. a) incubator
  2. b) colony county
  3. c) spectrophotometer
  4. d) chemostat

Answer: c

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

15) Acidophiles would be expected to grow best at a pH of _____.

  1. a) 3
  2. b) 6
  3. c) 9
  4. d) 12

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

16) An obligate psychrophile would produce a turbid culture at ________ degrees Celsius.

  1. a) 15
  2. b) 30
  3. c) 45
  4. d) 60

Answer: a

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

17) Most human pathogens are _____.

  1. a) psychrophiles
  2. b) mesophiles
  3. c) thermophiles
  4. d) acidophiles

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

18) Which of the following is most likely to have evolved to live in the deep layers of mud, where there is a complete lack of free oxygen?

  1. a) Obligate aerobe
  2. b) Obligate anaerobe
  3. c) Facultative anaerobe
  4. d) Aerotolerant anaerobe

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

19) Which type of cell will generally shift to aerobic metabolism when oxygen is available but will carry on fermentation otherwise?

  1. a) aerotolerant anaerobes
  2. b) facultative anaerobes
  3. c) obligate anaerobes
  4. d) obligate aerobes

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

20) Capnophiles grow best under conditions of _____.

  1. a) high carbon dioxide
  2. b) low carbon dioxide
  3. c) high osmotic pressure
  4. d) low osmotic pressure

Answer: a

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

21) The toxic effects of the byproducts of oxygen metabolism are reduced by which of the following?

  1. a) Catalase
  2. b) Superoxide dismutase
  3. c) Lactase
  4. d) Two of the above

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

22) Where would you expect to find a barophile?

  1. a) At the bottom of the ocean
  2. b) In unpasteurized milk
  3. c) In the large intestine
  4. d) In sewage

Answer: a

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

23) When cells are placed in a hypertonic environment they will undergo ________ .

  1. a) lysis
  2. b) no change in size
  3. c) swelling of the cell which is contained by the cell wall
  4. d) plasmolysis

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

24) Halophiles require an environment with a high concentration of ________ for optimal growth.

  1. a) sugar
  2. b) alcohol
  3. c) salt
  4. d) phosphorous

Answer: c

Difficulty: Easy

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

25) Organisms with special nutritional needs are said to be _____.

  1. a) barophiles
  2. b) fastidious
  3. c) aerobes
  4. d) none of the above

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

26) Which of the following is considered a trace element?

  1. a) carbon
  2. b) zinc
  3. c) sulphur
  4. d) phosphorous

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

27) Starch would be broken down to maltose by which of the following exoenzymes?

  1. a) gelatinase
  2. b) amylase
  3. c) caseinase
  4. d) lipase

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

28) Which of the following statements about bacterial growth is false?

  1. a) Agar is used as a solidifying agent in some types of media.
  2. b) Bacteria growing in a liquid culture will generate colonies.
  3. c) A turbid culture is indicative of bacterial growth.
  4. d) Each bacterium plated will represent a colony-forming unit.

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

29) Exoenzymes:

  1. a) produced by gram positive rods act in the medium around the organism
  2. b) are released by the golgi apparatus into the cytoplasm where they act
  3. c) produced by gram negative rods act in the periplasmic space
  4. d) two of the above

Answer: d

Difficulty: Hard

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

30) All of the following are ways microorganisms adapt to limited nutrients except:

  1. a) synthesize increased amount of enzymes for uptake and metabolism of limited nutrients
  2. b) form metabolically active highly resistant endospores
  3. c) synthesize enzymes needed to use a different nutrient source
  4. d) adjust the rate at which they metabolize nutrients

Answer: b

Difficulty: Hard

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

31) Sporulation occurs in:

  1. a) Clostridium
  2. b) Staphylocoocus
  3. c) Klebsiella
  4. d) Citrobacter

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

32) Endospores are:

  1. a) metabolically active
  2. b) reproductive structures
  3. c) found mostly in Gram negative organisms
  4. d) protective structures

Answer: d

Difficulty: Easy

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

33) Sporulation usually occurs in response to a/an _____.

  1. a) decrease in the level of carbon or nitrogen
  2. b) increase in temperature
  3. c) decrease in the amount of water
  4. d) increase in ultraviolet radiation

Answer: a

Difficulty: Medium

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

34) A decrease in the amount of nitrogen to a culture of Clostridium botulinum would induce _____.

  1. a) activation
  2. b) germination
  3. c) sporulation
  4. d) outgrowth

Answer: c

Difficulty: Medium

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

35) Within a bacterial endospore, the spore is most closely surrounded by the _____.

  1. a) spore membrane
  2. b) cortex
  3. c) cell membrane
  4. d) spore coat

Answer: a

Difficulty: Medium

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

36) Which of the following does not contribute to endospore resistance to unfavorable conditions?

  1. a) Dipicolinic acid and calcium ions in the core
  2. b) Cortex
  3. c) Spore coat
  4. d) Germination proper

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

37) Which of the following is not a stage in endospores returning to the vegetative state?

  1. a) Traumatic agent such as low pH or heat damages the coat.
  2. b) Outgrowth occurs in a medium with adequate nutrients.
  3. c) Divisions of the endospores early in their development.
  4. d) Water and nutrients penetrates damaged coat.

Answer: c

Difficulty: Hard

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

38) A culture that contains only a single species of organism is known as a _____.

  1. a) pure culture
  2. b) Koch culture
  3. c) mixed culture
  4. d) contaminated culture

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

39) The streak plate method produces pure cultures by separating individual bacterial cells from one another by _____.

  1. a) dragging them across a solid surface
  2. b) dispersing them in liquid media
  3. c) killing off those cells that are not able to survive in hot agar
  4. d) embedding some cells in the agar so that they are exposed to lower concentrations of oxygen

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

40) The pour plate method of isolating pure cultures _____.

  1. a) relies on the fact that liquid agar will solidify as it cools
  2. b) is useful for growing microaerophiles
  3. c) results in some organisms growing embedded in the agar
  4. d) all of the above

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

41) A growth medium consisting of only known amounts of water, magnesium, calcium chloride, potassium and glucose would be considered:

  1. a) a defined synthetic medium
  2. b) a complex medium
  3. c) a chemically nondefined medium
  4. d) two of the above

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

42) A growth medium consisting of only water, glucose and beef extract would be considered _____.

  1. a) a defined synthetic medium
  2. b) a complex medium
  3. c) a chemically defined medium
  4. d) two of the above

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

43) A media on which Gram positive organism turn green and Gram negative organisms turn blue would be _____.

  1. a) selective
  2. b) differential
  3. c) complex
  4. d) enriched

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

44) Sabourard’s agar has a low pH which encourages the growth of molds and discourages the growth of bacteria. Sabourard’s agar could best be described as being:

  1. a) selective
  2. b) differential
  3. c) complex
  4. d) enriched

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

45) Bacteria that ferment lactose grow as red colonies on MacConkey’s agar while those that do not ferment lactose are transparent. MacConkey’s agar can best be described as being:

  1. a) selective
  2. b) differential
  3. c) complex
  4. d) enriched

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

46) A candle jar would be used for growing:

  1. a) Gram negative organisms
  2. b) fastidious organisms
  3. c) thermophiles
  4. d) microaerophiles

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

47) A living, growing culture whose purpose is to maintain a pure culture of an organism indefinitely is a _____.

  1. a) colony
  2. b) stock culture
  3. c) sporulating culture
  4. d) broth culture

Answer: b

Difficulty: Easy

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

48) Which of the following statements about liquid media and agar is false?

  1. a) Both chocolate agar and blood agar contain blood.
  2. b) Stock cultures are never directly used for laboratory studies.
  3. c) A differential media will allow some bacteria to grow and stop the growth of others.
  4. d) A selective media will suppress the growth of some microbes.

Answer: c

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

49) Microaerophiles:

  1. a) grow best when the environment has a small amount of carbon dioxide.
  2. b) grow best when the environment has a small amount of free oxygen.
  3. c) need a high concentration of carbon dioxide.
  4. d) need a high concentration of oxygen.

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

50) Chocolate agar:

  1. a) contains blood
  2. b) is used exclusively for stock cultures
  3. c) is nutrient poor
  4. d) is a selective agar plate

Answer: a

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

51) ______ techniques must be strictly adhered to prevent the accidental contamination of stock cultures.

  1. a) Germination
  2. b) Selective
  3. c) Differential
  4. d) Aseptic

Answer: d

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.4 Culturing Bacteria

52) Nonculturable organisms:

  1. a) are rare.
  2. b) can be identified based on their DNA.
  3. c) can only be seen on selective agar plates.
  4. d) have defined generation times.

Answer: b

Difficulty: Medium

Learning Objective 1: LO 6.4 Compare the various types and purposes of culture media such as selective, enrichment, and differential media.

Section Reference 1: Section 6.5 Living, But Nonculturable, Organisms

53) During this phase, organisms produce large amounts of ATP.

  1. a) A
  2. b) B
  3. c) C
  4. d) D

Answer: a

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

54) This phase decreases at a logarithmic rate.

  1. a) A
  2. b) B
  3. c) C
  4. d) D

Answer: d

Difficulty: Easy

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

55) Microbes that live in this environment actively transport _____ out of their cells.

  1. a) potassium
  2. b) oxygen
  3. c) sodium
  4. d) nitrogen

Answer: c

Difficulty: Easy

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

Question Type: Essay

56) Draw and label a standard growth curve. Describe each of the 4 phases. Why do you think bacteria do not continue to double indefinitely? You sample a culture that has reached the fourth phase after 2 days, can you think of one reason why the culture would begin to increase on day 4?

Answer: Growth curve should have a flat lag phase, followed by an upward sloping log phase, then a flat stationary phase and lastly a downward sloping decline or death phase. The four phases are : 1) lag phase -the organisms are metabolically active synthesizing DNA and enzymes but not increasing in number; 2) log phase organisms are dividing exponentially; 3) stationary phase -number of new cells produced equals number of cells dying; 4) decline phase -where many cells have lost their ability to divide and are dying due to toxin buildup and nutrient deprivation.

Bacteria cannot increase exponentially forever as the amount of nutrients will always eventually be consumed or limited. Also toxic byproducts of metabolism would eventually build up.

One reason for the culture to increase again on day 4 is scavenging; in this case the dying cells release their cell components as nutrients that the remaining cells can use to grow. Another could be the production of spores. Or there could be a mutation that arises that allows the bacteria to grow on a new nutrient.

Difficulty: Medium

Learning Objective 1: LO 6.1 Discuss what is meant by “growth” when referring to microbes and the ways in which it can be measured.

Section Reference 1: Section 6.1 Growth and Cell Division

57) What is sporulation? What triggers sporulation? In bacteria that form endospores generally only a fraction of the total population sporulate and the process takes over eight hours. Explain why it would be harmful for the whole population to sporulate. Is it better to continuously form spores or wait to sporulate when conditions become unfavorable?

Answer: Sporulation is the formation of endospores which are not metabolically active and are very resistant to extreme conditions and stress. The endospore cannot divide but can wake up when conditions for growth are restored. Endospores are generally triggered during stationary phase in response to environmental, metabolic and cell cycle signals.

It would be harmful for the whole population to sporulate if the conditions changed rapidly or not predictably, if for example within those eight hours the nutrients where restored then the whole population would be unable to respond as they would still be sporulating. Also if there were a false alarm it would also be harmful for the whole population to sporulate.

An advantage to continuously forming spores are mainly in rapidly changing or unpredictable conditions as there will always be a safety net (spores) already formed. A disadvantage to continuously forming spores is that spores are not dividing, therefore they do not contribute to increasing the size of the bacteria population (e.g., fitness) and could be seen as diverted resource.

Difficulty: Hard

Learning Objective 1: LO 6.3 Examine the process of endospore formation and the advantages it provides to the bacteria capable of undergoing this process.

Section Reference 1: Section 6.3 Sporulation

58) Imagine NASA sends you a specimen from a planet that they believe contains an extraterrestial bacterial species. You are the microbiologist in charge of determining how to grow the extraterrestial bacteria. Many factors may affect the growth of extraterrestial bacteria. Choose two and describe how you would test their effects.

Answer: Physical factors that could affect the growth of this extraterrestial bacterium (along with how to test them in parenthesizes) include: acidity and alkalinity (grow along range of pH broths), temperature (grow along a temperature range), quantity of oxygen and perhaps other gases in the environment (grow in incubators with different quantities of oxygen or in bell jars or observe where the pattern of growth is in nutrient broth), moisture (try a range of humidities), hydrostatic or osmotic or gravitational pressure (try a range of pressures), radiation (try irradiating the bacteria).

Nutritional factors that could affect the growth of this extraterrestial bacterium (to test them one would simply vary the concentration or quality of the nutrients in the broth) include: carbon sources, nitrogen sources, sulfur, phosphorus, trace elements and vitamins. In addition growth could depend on the nutritional complexity (to test would need to vary complexity of broths).

Difficulty: Easy

Learning Objective 1: LO 6.2 Review the physical and nutritional factors that can influence microbial growth.

Section Reference 1: Section 6.2 Factors Affecting Bacterial Growth

Chapter 9: An Introduction to Taxonomy: The Bacteria

Question Type: Multiple Choice

1) Which one of the following is a prokaryote without a cell wall?

  1. a) Virus
  2. b) Cyanobacterium
  3. c) Mycoplasma
  4. d) Rickettsia

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

2) Which one of the following microorganisms was once called blue-green algae?

  1. a) Mycoplasmas
  2. b) Cyanobacteria
  3. c) Chlamydiae
  4. d) Rickettsia

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

3) Which one of the following microorganisms has its own kingdom in the five-kingdom of classification?

  1. a) Viruses
  2. b) Algae
  3. c) Bacteria
  4. d) Fungi

Answer: d

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

4) The five kingdom system of classification was developed by _____.

  1. a) Charles Darwin
  2. b) Robert Hooke
  3. c) Louis Pasteur
  4. d) Robert Whittaker

Answer: d

Difficulty: Easy

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

5) All of the following are considered eukaryotes except:

  1. a) Archea
  2. b) Fungi
  3. c) Protozoa
  4. d) Humans

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

6) The binomial name of a microbe is composed of its _____.

  1. a) kingdom and genus names
  2. b) genus name and a species modifier
  3. c) family and class names
  4. d) genus and family names

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

7) The science of classification is generally known as _____.

  1. a) nomenclature
  2. b) taxonomy
  3. c) morphology
  4. d) dichotomy

Answer: b

Difficulty: Easy

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

8) Classification is necessary to ______.

  1. a) establish criteria for identifying organisms
  2. b) arrange related organisms into groups
  3. c) provide information on how organisms evolved
  4. d) All of the above

Answer: d

Difficulty: Easy

Learning Objective 1: LO 9.1 Asses the value of the taxonomic hierarchies that have been constructed.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

9) Binomial nomenclature was originated by ______.

  1. a) Louis Pasteur
  2. b) Robert Koch
  3. c) Hans Delbruck
  4. d) Carolus Linnaeus

Answer: d

Difficulty: Easy

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

10) In the name Escherichia coli, Escherichia refers to the ________ of the bacteria.

  1. a) class
  2. b) phylum
  3. c) species
  4. d) genus

Answer: d

Difficulty: Easy

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

11) Which of the following organisms shows the proper use of binomial nomenclature?

  1. a) escherichia coli
  2. b) Escherichia Coli
  3. c) Escherichia coli
  4. d) escherichia coli

Answer: c

Difficulty: Easy

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

12) Which of the following levels of classification would contain the greatest number of organisms?

  1. a) Phylum
  2. b) Order
  3. c) Genus
  4. d) Class

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

13) The correct order of taxonomic hierarchies (from most broad to most specific) is _____.

  1. a) class, order, family, phylum
  2. b) order, family, class, phylum
  3. c) phylum, class, order, family
  4. d) phylum, class, family, order

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

14) Organisms in the same ________ are more closely related than are organisms in the same ________.

  1. a) phylum, genus
  2. b) class, order
  3. c) family, phylum
  4. d) phylum, order

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.1 Taxonomy: The Science of Classification

15) A strain is a subgroup of a _____.

  1. a) phylum
  2. b) class
  3. c) family
  4. d) species

Answer: d

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.2 Using a Taxonomic Key

16) A tool used by biologist that involves asking a series of “either-or” questions which eventually leads to the identification of an organism is a/an _____.

  1. a) species key
  2. b) evolutionary tree
  3. c) dichotomous key
  4. d) binary chart

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.2 Using a Taxonomic Key

17) A bacterial strain contains _____.

  1. a) several species
  2. b) several families
  3. c) a subgroup of a species with some of the same characteristics
  4. d) a subgroup of a genus which have permanent genetic differences

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.2 Using a Taxonomic Key

18) Which of the following questions would not be a good choice for a dichotomous key?

  1. a) Are the cells rod shaped?
  2. b) Are the cells Gram negative?
  3. c) Do the cells ferment glucose?
  4. d) Where is the cell usually found?

Answer: d

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.2 Using a Taxonomic Key

19) Organisms are generally classified according to _____.

  1. a) cell size
  2. b) evolutionary relationships
  3. c) colony color
  4. d) None of these choices

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.2 Using a Taxonomic Key

20) Which of the following is a reason that bacteria cannot be classified in the same way as animals?

  1. a) Some bacteria are not motile.
  2. b) Bacteria do not reproduce sexually.
  3. c) Bacteria are single celled organisms.
  4. d) Bacteria are prokaryotic organisms.

Answer: b

Difficulty: Easy

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

21) The historic two-kingdom system of classification divided all organisms into either ________ or ________ .

  1. a) animals, bacteria
  2. b) plants, animals
  3. c) eukaryotic, prokaryotic
  4. d) motile, nonmotile

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

22) Before bacteria received a kingdom of their own they were generally classified along with:

  1. a) protists
  2. b) animals
  3. c) fungi
  4. d) viruses

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

23) Which of the following characteristics is not found in all cellular life forms?

  1. a) Cells that are bounded by a membrane
  2. b) Genetic information carried in the form of DNA
  3. c) Ability to convert light energy to chemical energy
  4. d) Ribosomes that produce proteins

Answer: c

Difficulty: Easy

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

24) All members of the historic Kingdom Monera are:

  1. a) cyanobacteria
  2. b) prokaryotes
  3. c) fungi
  4. d) protists

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

25) A prokaryotic cell would have been assigned to which of the taxonomic Kingdoms?

  1. a) Monera
  2. b) Animalia
  3. c) Fungi
  4. d) Protista

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

26) A eukaryotic, unicellular organism with no cell wall would be classified as _____.

  1. a) Monera
  2. b) Animal
  3. c) Fungi
  4. d) Protista

Answer: d

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

27) A eukaryotic, multicellular organism that has no cell wall would be classified as a/an:

  1. a) moneran
  2. b) animal
  3. c) fungus
  4. d) protist

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

28) The Kingdom Monera was also known as the Kingdom _____.

  1. a) Bacteria
  2. b) Eubacteria
  3. c) Prokaryotae
  4. d) Archaeobacteria

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

29) Within the Kingdom Monera, the group of most interest to medical microbiologists is the:

  1. a) cyanobacteria
  2. b) eubacteria
  3. c) archaeobacteria
  4. d) prokaryotic bacteria

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

30) Bacteria found in extreme environments (e.g., high heat, very high salt concentration) would best be described as a member of the _____.

  1. a) eubacteria
  2. b) prokaryotae
  3. c) cyanobacteria
  4. d) archaeobacteria

Answer: d

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

31) In the five-kingdom scheme of classification, algae are classified along in the Kingdom:

  1. a) Monera
  2. b) Protista
  3. c) Plant
  4. d) Protista and Plant

Answer: d

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

32) Which Kingdom includes all animals derived from zygotes?

  1. a) Fungi
  2. b) Plantae
  3. c) Animalia
  4. d) Protista

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

33) Fungi can be differentiated from plants by the fact that _____.

  1. a) fungi are all unicellular, plants are all multicellular
  2. b) fungi do not have a cell wall, plants have a cell wall
  3. c) fungi cannot photosynthesize, plants can photosynthesize
  4. d) fungi are prokaryotic, plants are eukaryotic

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

34) Which groups of animals are not usually of concern to the microbiologist?

  1. a) ticks
  2. b) tapeworms
  3. c) fleas
  4. d) moths

Answer: d

Difficulty: Easy

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

35) Fossil studies indicate that life on earth first arose about 4 billion years ago. How many billion years ago did multicellular living organisms appear in the fossil record?

  1. a) 1
  2. b) 2
  3. c) 3
  4. d) 4

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

36) In the five-kingdom system of classification, _____.

  1. a) viruses cannot be classified
  2. b) all prokaryotic organisms are found in the kingdom eubacteria
  3. c) all organisms that can photosynthesize are found in the plant kingdom
  4. d) a domain is a division of a kingdom

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

37) The three-domain system of classification does not include the _____.

  1. a) archaea
  2. b) eukarya
  3. c) monera
  4. d) bacteria

Answer: c

Difficulty: Easy

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

38) According to the three-domain classification system an organism with a cell wall made of peptidoglycan would belong to the _____.

  1. a) Bacteria
  2. b) Archaea
  3. c) Eukarya
  4. d) none of the above

Answer: a

Difficulty: Easy

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

39) According to the three-domain classification system an organism with cells measuring more than 10 micrometers across would most likely belong to the ______.

  1. a) eukarya
  2. b) bacteria
  3. c) archaea
  4. d) eukarya, bacteria and archaea would be equally likely

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

40) According to the three-domain classification system, modern plants and animals belong to which Domain?

  1. a) bacteria
  2. b) eukarya
  3. c) archaea
  4. d) none of the above

Answer: b

Difficulty: Easy

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

41) In the three-domain classification system _____.

  1. a) all prokaryotes are grouped into the same domain
  2. b) eukaryotes are found in two of the domains
  3. c) archea may be more closely related eukaryotes than to bacteria
  4. d) two of the above

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

42) Organisms that degrade organic molecules to methane belong to the domain _____.

  1. a) Archaea
  2. b) Eukarya
  3. c) Bacteria
  4. d) Monera

Answer: a

Difficulty: Easy

Learning Objective 1: LO 9.3 Appraise the need for the three-domain classification system.

Section Reference 1: Section 9.4 The Three-Domain Classification System

43) Viruses are not assigned to any Kingdom because _____.

  1. a) there are too few viruses to bother
  2. b) viruses are not cellular life forms
  3. c) virology is not a recognized branch of microbiology
  4. d) none of the above, viruses are grouped with the bacteria

Answer: b

Difficulty: Easy

Learning Objective 1: LO 9.4 Explain why viruses are classified independently of other life forms.

Section Reference 1: Section 9.5 Classification of Viruses

44) Genetic homology determines evolutionary relationships among organisms based on:

  1. a) the similarity of antibody reactions between species
  2. b) the similarity of DNA between species
  3. c) morphological similarities between species
  4. d) the number of traits shared by two organisms

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

45) If an organism contains 13% adenine in its DNA, its GC content is _____.

  1. a) 13%
  2. b) 26%
  3. c) 74%
  4. d) 37%

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

46) In DNA hybridization experiments, DNA from two closely related organisms will show _____.

  1. a) very little annealing
  2. b) a high percentage of annealing
  3. c) 100% annealing
  4. d) it is impossible to tell

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

47) Polyacrylamide gel electrophoresis is used to separate _____.

  1. a) DNA by GC content
  2. b) proteins by size
  3. c) DNA by nucleotide sequence
  4. d) proteins by amino acid sequence

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

48) The 16S ribosomal subunit is used to study evolutionary relatedness because _____.

  1. a) it is the easiest type of RNA to sequence
  2. b) ribosomes have evolved very slowly due to their essential roles in cells
  3. c) ribosomes evolve very quickly so differences are easy to spot
  4. d) None of the above

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

49) In phage typing, bacteria that are lysed by the same type of bacteriophage are thought to be:

  1. a) more closely related to one another
  2. b) less closely related to one another
  3. c) more closely related to the bacteriophage
  4. d) less closely related to the bacteriophage

Answer: a

Difficulty: Medium

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

50). Which of the following criteria is not commonly used to classify Bacteria?

  1. a) Morphology
  2. b) Shape of ribosomes
  3. c) Staining characteristics
  4. d) Biochemical characteristics

Answer: b

Difficulty: Medium

Learning Objective 1: LO 9.6 Evaluate Bergey’s contributions to bacterial classification and identification.

Section Reference 1: Section 9.7 Bacterial Taxonomy and Nomenclature

51) Rickettsiae and Chlamydiae are unusual in that they _____.

  1. a) are sometimes gram negative and sometimes gram positive
  2. b) have no cell walls
  3. c) must live inside other living cells
  4. d) are extremely large

Answer: c

Difficulty: Medium

Learning Objective 1: LO 9.6 Evaluate Bergey’s contributions to bacterial classification and identification.

Section Reference 1: Section 9.7 Bacterial Taxonomy and Nomenclature

52) A useful technique for comparing different bacterial species based on if they are susceptible to infection by the same virus is called _____.

  1. a) protein profile
  2. b) virus profile
  3. c) phage typing
  4. d) serology

Answer: c

Difficulty: Easy

Learning Objective 1: LO 9.6 Evaluate Bergey’s contributions to bacterial classification and identification.

Section Reference 1: Section 9.7 Bacterial Taxonomy and Nomenclature

53) In a bacterial species with multiple chromosomes, _____.

  1. a) having one or two chromosomes has no evolutionary impact
  2. b) it is very simple to distinguish between a chromosome and plasmid purely based on size
  3. c) scientists postulate the use of a microfilament structure to ensure partition of both chromosomes to each daughter cell
  4. d) duplicate genes that differ by mutations classify the organism as diploid

Answer: c

Difficulty: Hard

Learning Objective 1: LO 9.6 Evaluate Bergey’s contributions to bacterial classification and identification.

Section Reference 1: Section 9.7 Bacterial Taxonomy and Nomenclature

54) The organisms represented in this illustration are members of the Kingdom _____.

  1. a) Protista
  2. b) Monera
  3. c) Plantae
  4. d) Fungi

Answer: b

Difficulty: Easy

Learning Objective 1: LO 9.2 Review the features of the five-kingdom classification system.

Section Reference 1: Section 9.3 The Five-Kingdom Classification System

55) Use the following dichotomous key to determine the identity of an organism with the following characteristics: not Gram (+), not Gram (-), not rod-shaped, not spherical-shaped, and it is comma-shaped.

  1. a) Spirochetes
  2. b) Vibrioids
  3. c) Corynebacteria
  4. d) Mycoplasma

Answer: d

Difficulty: Medium

Learning Objective 1: LO 9.1 Assess the value of the taxonomic hierarchies that have been constructed, explaining how a dichotomous key works.

Section Reference 1: Section 9.2 Using a Taxonomic Key

Question Type: Essay

56) How do lateral gene transfer and symbiosis complicate both the three-domain or five-kingdom treelike structure? Where do viruses, viroids and prions fit in today’s taxonomy? Are they classified based on phylogeny or morphology?

Answer: The branching treelike structure suggests that the domains or kingdoms have remained isolated. However, lateral gene transfer allows for a Bacteria to have ¼ of its genome comprised of Archaean genes. It is clear that lateral gene transfer means there are connecting branches between the domains/kingdoms and that organisms have multiple origins of ancestry. In addition, symbiosis has lead to some components of an organisms genomes coming from other organisms, such as chloroplasts and mitochondria within eukaryotic cells. These symbiotic additions of genes also lead to connecting branches between the domains/kingdoms or a shrub-like structure.

Viruses are classified by their chemical and physical characteristics. Viroids are a fragment of RNA and a prion is a protein molecule which folds incorrectly. Both viroids and prions are classified based on their molecular characteristics (viroids based on RNA sequence and prions based on amino acid sequence). Viruses, viroids and prions are classified based on their molecular constitution (morphology) not their evolutionary relationships (phylogeny).

Difficulty: Medium

Learning Objective 1: LO 9.2 Explain how a dichotomous key works; LO 9.4 Explain why viruses are classified independently of other life forms.

Section Reference 1: Section 9.2 Using a Taxonomic Key; Section 9.5 Classification of Viruses

57) What is a species? How are species determined for bacteria and plants/animalsIs the notion of a species still relevant when morphology, ecology/environmental pressures and phylogeny may present such differing ways in which to organize organisms and their relatedness.

Answer: Species is the basic unit of biological classification or the narrowest division for a group of organisms with many common characteristics or is the group of organisms that are distinguished from others based on some characteristic and titled with the binomial nomenclature. Species is determined in plants and animals based on whether a male and a female are able to reproduce sexually. Species is determined in bacteria based on the similarities found among its members.

Second part is personal opinion. But one could argue that the morphology/sexual reproductive species concept is best as we have already defined a working classification system based on it and it can be easily defined/tested as it is based on observable phenomena. Or argue that an ecological species would allow us to explore the ecological and evolutionary processes controlling how resources are divided up. Or argue that an evolutionary species would allow us to determine clearly how much diversity can be tolerated within the unity of a species.

Difficulty: Hard

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

58) To classify new microbes, modern genetic techniques are employed. Why would the evolutionarily relatedness of genes (genetic homology) be more useful than morphology? How are ribosomal RNAs used to study evolutionary relationships among organisms?

Answer: Genetic homology allows for one to group closely related organisms and to separate them from less closely related ones. Morphology observed could be due to convergent evolution whereas genetic differences allow us to clearly distinguish whether there was a common ancestor. Ribosomal RNA is useful because mutations are rarely tolerated and so ribosomes have evolved very slowly. This allows for distinguishing between two species based on the fixed changes observed in 16S rRNA.

Difficulty: Medium

Learning Objective 1: LO 9.5 Describe some of the scientific methods employed by evolutionary biologists such as numerical taxonomy, genetic homology comparisons, and serological studies.

Section Reference 1: Section 9.6 The Search for Evolutionary Relationships

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